Tangle about the missing ending for a long time (2,6)
I believe the answer is:
at length
'missing ending for a long time' is the definition.
I can't tell whether this defines the answer.
'tangle about the' is the wordplay.
I cannot quite see how this works, but
an anagram of 'tangle' is 'atleng' which is within the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
A single letter 'h' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for at length that I've seen before include "Taking a long time like long-winded speech" , "Exhaustively" , "In detail, fully" , "eventually" , "In great detail" .)